President Barack Obama has reaffirmed relations between the United States and Poland.
He praised Poland's economic growth and its support of pro-democracy movements in North Africa and the Middle East.
The relationship between the US and Poland suffered when Mr Obama halted a plan to build missiles on Polish soil two years ago.
The BBC says it was seen as deference to Russia and as a sign of a lack of commitment to Poland.
But Mr Obama said the shelving of his predecessor's plan did not put Poland or the region at risk.
He repeated his insistence that the strategy was about reaffirming the NATO principles of mutual defence, saying it allowed their two countries to deal with shared threats.
Prime Minister Donald Tusk said he had been reassured by Mr Obama's words.
At a brief press conference with Mr Tusk, Mr Obama said Poland was ''one of our strongest and closest allies and a leader in Europe'' and ''a living example of what is possible when countries take reform seriously''.
He praised efforts by members of the Solidarity movement to offer support to Egypt's post-revolution government.
However, Mr Obama has not granted Poland's desire for a visa waiver for its citizens travelling to the United States.